Substituted semicarbazones, thiosemicarbazones and isothiosemicarbazones and salts thereof, intermediates therefor, synthesis thereof, and the use of said compounds for the control of weeds.
Exploiting Hydrazones To Improve the Efficiency of 6π-Electrocyclization Reactions of 1-Azatrienes
作者:Matthew P. Ball-Jones、Jasper Tyler、Helena Mora-Radó、Werngard Czechtizky、María Méndez、Joseph P. A. Harrity
DOI:10.1021/acs.orglett.9b02455
日期:2019.9.6
The greater geometric lability of hydrazones compared to that of oximeethers is used as a basis to overcome the reluctance of Z-oxime ether azatrienes to undergo electrocyclization toward the synthesis of borylated (heteroaromatic) pyridines and ring-fused analogues. Such hydrazones now allow access to previously inaccessible tri- and tetrasubstituted 3-borylpyridines in high yields.
Rhodium(II)-Catalyzed Cyclization of Bis(N-tosylhydrazone)s: An Efficient Approach towards Polycyclic Aromatic Compounds
作者:Ying Xia、Zhenxing Liu、Qing Xiao、Peiyuan Qu、Rui Ge、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201201374
日期:2012.6.4
Ahead of the PAC: Polycyclicaromaticcompounds (PACs) can be easily accessed by the combination of Suzuki–Miyaura cross‐coupling and a [Rh2(OAc)4]‐catalyzed carbene reaction using easily available bis(N‐tosylhydrazone)s as intermediates (see scheme; Ts=4‐toluenesulfonyl).
Metal-free visible light-promoted synthesis of isothiazoles: a catalytic approach for N–S bond formation from iminyl radicals under batch and flow conditions
applying photoredoxcatalysis. This simple strategy features mild conditions, broad scope and wide functional group tolerance representing a new enviromentally friendly option to prepare these highly valuable heterocycles. Furthermore, the synthetic value of the method is highlighted by the preparation of a natural product derivative and the implementation of the reaction in a continuousflow setup.
A base-promoted formal [2 + 2]-cycloaddition of 2-acyl-2′-vinyl-1,1′-biaryls was developed to provide polycyclic cyclobutanols as a step toward the synthesis of substituted polycyclic aromatic hydrocarbons and their heterocyclic analogues.